Insect repellents for application to the human skin are widely used by outdoorsmen. Such compositions, which come in the form of liquids, creams, pastes and gels, are rubbed or sprayed on the skin. Covered areas are protected from insect bites by the repellent nature of the composition, which dissuades certain insects, including mosquitoes, from alighting.
The most widely used insect repellent active in use today is N,N-diethyl-m-toluamide, sometimes referred to as "DEET," which is described in U.S. Pat. No. 2,932,665. DEET is very effective in protecting an outdoorsman from insects, provided it is properly applied such that it adequately covers the skin of the user. But insects, such as mosquitoes, frequently will alight on areas where the repellent composition has been "wiped" or "rubbed" off or on areas of weak or uneven coverage.
Maintaining thorough protection of all exposed skin, and thus maintaining effective insect repellence of all exposed skin, is of great importance to many outdoorsmen, particularly hunters such as duck hunters, who remain as motionless as possible in a duck blind for long periods, and military personnel operating in insect infested areas.
Such outdoorsmen often apply camouflage creams and the like to their skin in an effort to obscure their presence to ducks, other game which they are hunting, or the enemy. Such camouflage compositions are heavily and darkly pigmented compositions suitable for application to the skin.
In order for such an outdoorsman to camouflage his skin and protect it from insects, he must apply two separate skin compositions--a camouflage composition and an insect repellent composition. Applying two separate compositions in two separate application steps is both inconvenient and time-consuming for outdoorsmen.
In addition, such piggybacked application of compositions on the skin unfortunately can tend to cause ineffective functioning of one or both of the compositions. For example, if an insect repellent composition is applied just prior to application of a camouflage cream, the insect repellent can be removed or made uneven such that its effectiveness is reduced, at least in certain areas. Or, if an insect repellent is applied after application of a camouflage composition, the camouflage can be removed or, more typically, made uneven and blotchy.
In short, the application of such compositions to the skin seriatim, in either order, leads to ineffectiveness of one or both of the functions they are intended to serve. Most notably, the effectiveness of the composition which is applied first is interrupted or reduced upon application of the composition which is applied second.